Where are the storms? Where are they heading? What cities are in their path? With severe weather season in full swing, these are some common questions that can be answered using data from current storm cells.

This article is the second in our series highlighting the severe weather-related features of the Aeris API. In our first article, we highlighted the various severe weather features of the Aeris API. This time, we will expand on the storm cells API endpoint and AMP layers.

The stormcells endpoint provides information on the individual storm cells across the United States, including Puerto Rico and Guam. Storm cell information is a radar-derived product that attempts to identify and track storm movement. Cell intensity and severe weather signatures within the cell, such as rotation and hail, are also reported. When available, the forecast track can be obtained as a polygon cone or as a line.

While our Aeris Weather API provides a lot of useful data about storms and severe weather, plotting them on a map tells a better weather story for a particular event. Our Aeris Maps Platform (AMP) provides you with many options for mapping storm cells.

Aeris Maps Platform (AMP) Storm Cell Layer

Our Aeris Maps Platform offers a layer allowing you to easily overlay storm cells onto static maps or use as tiles for use with any mapping library.

For example, here’s a static map with radar and storm cells centered on Atlanta, GA at zoom level 8:

In this example, AMP is plotting all available cells, even general storms that indicate no significant threats other than light to moderate rainfall.

AMP allows you to filter the storm cells to just show the ones with potential threats, such as hail, significant rotation, and tornadic signatures. Simply adjust the layer name from
stormcells to
stormcells-major :

Storm cells using AIM

Our Aeris Interactive Maps (AIM) SDK offers an option for adding storm cells as point data instead of a static image overlay. As explained in the AIM point data documentation, the following code provides an example map with cells displayed as individual markers, or you can view a live example.

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varaerisMapBuilder=newaeris.interactive.MapAppBuilder({

apiId:'[clientId]',

apiSecret:'[clientKey]',

el:'#map-canvas',

modules:{

pointData:{

objects:[{

type:"StormCells",

group:"Points",

cluster:false,

selected:true

}]

}

}

});

aerisMapBuilder.start();

Aeris Interactive Storm Cells

Rendering storm cells as point data using a mapping library allows you to add interaction to your cells, such as clicking or tapping on a cell’s marker on the map to display more details about that cell. Additionally, you could receive a list of major cities currently in the forecast path of a particular cell.

Example interaction with storm cell with AIM

Storm cells using a Leaflet map

Leaflet.js is a commonly used open-source mapping library. Integrating storm cells with a Leaflet map is simplified since the Aeris API supports outputting data in GeoJSON. GeoJSON is a common method for transferring geospatial data between systems and is supported by many modern mapping platforms, such as Leaflet.

When adding storm cells to a Leaflet map, an API query similar to the following could be used:

The above URL would fetch up to 1000 storm cells across the US. With this URL you could follow the process utilized with our storm reports article to add the storm cells to your Leaflet map.

Customizing the cell’s styling beyond the mapping library’s defaults will greatly enhance your visualization. A good example of this is demonstrated within our Storm Threats Map and the stormcells.js class which fetches and applies styling for the cells on a Leaflet map.

Aeris Weather API Storm Cell Data

Nearby storm cells

The API will return the 10 closest cells within a 25-mile radius if you pass a location to the storm cells endpoint:

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stormcells/minneapolis,mn?limit=10

The API will return “no data available” if no storm cells are found within 25 miles of the location. The location can be a city, state, US zip code, coordinate or any of the other supported place formats.

To extend the radius of the search to 50 miles, we can add
radius=50miles to the query:

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stormcells/minneapolis,mn?radius=50miles&limit=10

Distance from storm cells

The
relativeTo JSON object for each storm cell result provides the bearing from the requested location and the distance:

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"relativeTo":{

"lat":41.85003,

"long":-87.65005,

"bearing":56,

"bearingENG":"NE",

"distanceKM":13.634,

"distanceMI":8.472

}

This information, combined with the cell’s direction and speed, are very useful for determining if the cell is approaching the location and how long it may take for the storm to arrive.

Filtering storm cells

When requesting storm cell data, the API will return information on any cell by default. This includes general storms that may not indicate significant weather threats. The storm cells endpoint provides a variety of filters to limit results.

For example, to limit the result to just storm cells with hail:

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stormcells/minneapolis,mn?limit=10&filter=hail

Or, limit to cells with intense rainfall:

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stormcells/minneapolis,mn?limit=10&filter=rainintense

Filters can also be combined, such as returning results that include hail and intense rainfall.

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stormcells/minneapolis,mn?limit=10&filter=hail,rainintense

Along with filters, the storm cells endpoint offers a variety of query options that can be used to limit results further. For example, find the 10 closest storm cells with a high probability of hail with a diameter 1″ or greater:

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stormcells/minneapolis,mn?limit=10&filter=hail&query=hailsize:1

We can also sort the results by potential hail size, largest to smallest, using the sort parameters:

Searching storm cells

One unique feature of the Aeris Weather API is the search action, which allows you to perform advanced queries that may not pertain to a specific location. When utilized with the storm cells endpoint, you have the ability to search across the entire US, a single state or multiple.

For example, return up to 100 storm cells that indicate a tornadic vortex signature (TVS) (if there are more than 100 cells with a tornadic signature at a given time, we may have bigger problems!):

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stormcells/search?filter=tornado&limit=100

Or, return up to 100 storm cells within the state of Minnesota that have a diameter estimated to be 1.5″ or greater in size, sorted by hail size:

Locations within a storm cell’s path

Most of the time storms will provide forecast path data, at which point the API will also provide a forecast cone to indicate the potentially affected locations. Using the affects action with the storm cells endpoint, you can obtain a list of the cities within an individual cell’s forecast.

A unique
id is provided with each storm cell response, which will look similar to
DXY_B4 . When you query the affects action, use the
id of the cell you wish to query and the API will return a list of cities within the storm’s forecast cone. Only cities with a population of 25,000 or more are returned by default:

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/stormcells/affects/DYX_B4?limit=10

The above request would return the top 10 locations, by population, within the forecast path of storm cell with id of
DYX_B4 . If you would like to return locations with a minimum population of 1,000, then you can add
query=pop:1000 :

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/stormcells/affects/DYX_B4?limit=10&query=pop:1000

Get started with storm cells

We’ve reviewed the many capabilities of the storm cells endpoint–from static maps and interactive maps, to querying the raw data directly. Severe weather season is well underway, so get started with our free developer account to experiment with integrating storm cell information to your own applications and alerting platforms today!